WO2001062701A1 - Process for preparation of formate esters or methanol and catalyst therefor - Google Patents

Abstract

A process for preparing formate esters or methanol and a catalyst therefor are provided, which little suffer from lowering in the activity even when the raw material contains CO2, water, or the like, and enable the preparation of the objective compounds at low temperature under low pressure. Specifically, a process for preparing methanol, characterized in that in preparing a formate ester by reacting carbon monoxide with an alcohol in the presence of an alkali metal catalyst and/or an alkaline earth metal catalyst, both a hydrogenolysis catalyst for formate esters and hydrogen are made to coexist additionally in the reaction system to thereby hydrogenate a formed formate ester into methanol.

Description

 Description Method for producing formate or methanol and its synthesis catalyst

 The present invention relates to a method for producing a formate or methanol and a synthesis catalyst thereof. More specifically, the present invention relates to a method for obtaining a product with high efficiency by using a catalyst having high resistance to a decrease in activity due to water, carbon dioxide, and the like when producing methanol from carbon monoxide and hydrogen, and to a catalyst therefor. Background technology

 Generally, when methanol is synthesized industrially, carbon monoxide and hydrogen (synthetic gas) obtained by steam reforming natural gas containing methane as the main component are used as raw materials for copper and zinc. It is synthesized under the severe conditions of 200-300 ° C and 5-25 MPa by the fixed bed gas phase method using a catalyst such as a system. This reaction is an exothermic reaction.However, it is difficult to efficiently remove heat due to poor heat conduction in the gas phase method. It is a process with difficulty in recycling. However, various plants are in operation, taking advantage of the fact that the reaction is not easily hindered by water and carbon dioxide contained in synthesis gas.

On the other hand, various methods for synthesizing methanol in the liquid phase to improve the heat removal rate are being studied. Among them, a method using a catalyst having a high activity at a low temperature (about 100 to 180 ° C.) has been attracting attention because it is thermodynamically advantageous for the production system. However, in these methods, a decrease in the activity due to water and carbon dioxide, which are often contained in the synthesis gas, was reported. Is not yet practical. Disclosure of the invention

 An object of the present invention is to solve the above-mentioned problems, and even if carbon dioxide, water, and the like are mixed in a raw material gas for formate or methanol, the degree of activity reduction of the catalyst is low, It is another object of the present invention to provide a catalyst and a method capable of synthesizing formate or methanol at low temperature and low pressure.

 The features of the present invention are as described below.

 (1) The production of formate ester, which comprises reacting carbon monoxide with an alcohol to produce a formate ester in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst. Method.

 (2)-When producing carbonic oxide and alcohols in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst to produce formate, the reaction system is further subjected to hydrogenolysis of formate. A method for producing methanol, comprising producing a methanol by hydrogenating a produced formate ester in the presence of a catalyst and hydrogen.

 (3) — Carbon dioxide and alcohols are reacted in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst to produce formate, and the resulting formate is separated. A method for producing methanol by hydrogenating the separated formate ester in the presence of hydrogen and hydrogen.

(4) An alcohol is converted from carbon monoxide and hydrogen in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst, and a catalyst containing Cu and Mn and Z or Re simultaneously. A method for producing methanol, comprising reacting to obtain methanol. (5) A method for producing a formate ester, which comprises reacting carbon monoxide with an alcohol to produce a formate ester, wherein the reaction is carried out in the presence of a catalyst containing Cu, Mn and / or Re at the same time. .

 (6) The production according to any one of (1) to (4), wherein the alkali metal catalyst or the alkaline earth metal catalyst is a catalyst containing an alkali metal salt or an alkaline earth metal salt. Method.

 (7) The hydrocracking catalyst is a solid catalyst, and an alkali metal catalyst and a Z or alkaline earth metal catalyst are supported on the solid catalyst and provided for the reaction. (2) or (3). For producing methanol.

 (8) The method according to any one of (1) to (5), wherein the alcohol is a primary alcohol.

 (9) A catalyst for methanol production, comprising an alkali metal catalyst and / or an alkaline earth metal catalyst supported on a solid catalyst for hydrogenolysis of formate.

 (10) A catalyst for producing methanol, comprising: an alkali metal catalyst and / or an alkaline earth metal catalyst; and a catalyst containing Mn and / or Re at the same time.

 (11) A catalyst for producing a formate ester, characterized by simultaneously containing Cu, Mn and / or Re.

 Hereinafter, the present invention will be described in detail.

The present inventors have conducted intensive studies, and as a result, using an alkaline metal-based catalyst and / or an alkaline earth metal-based catalyst that is not substantially poisoned by water and / or carbon dioxide, water and / or carbon dioxide The present inventors have found that formic acid esters can be produced from carbon monoxide and alcohols even when carbon is mixed, and have led to the present invention. Examples of these alkali metal systems include metal compounds such as lithium, potassium, sodium, and cesium or simple substances, while alkali earth metal systems include calcium compounds. Examples include metal compounds such as shim, magnesium, palladium, and stotium, or simple substances. As these metal compounds, metal salts or metal oxides are suitable, and more preferably, metal salts such as carbonates, nitrates, phosphates, acetates, and formates. It is possible. Metallic alkoxides (methoxide, ethoxide, etc.) are excluded because they are substantially poisoned by the above substances. These catalysts can also be used by being supported on a general carrier by an ordinary method. The alcohol used in the reaction may be a chain or alicyclic hydrocarbon having a hydroxyl group, phenol or a substituted product thereof, or thiol or a substituted product thereof. These alcohols may be primary, secondary or tertiary, but primary alcohols are preferred in terms of reaction efficiency and the like, and lower alcohols such as methyl alcohol and ethyl alcohol are most common. is there. The reaction can be performed in either a liquid phase or a gas phase, but a system that can select mild conditions can be employed. Specifically, the temperature is selected from about 70 to 250, a pressure of 3 to 70 atm, a time of 5 minutes to 10 hours, but is not limited thereto. The alcohol may be used in such an amount that the reaction proceeds, but an amount larger than that may be used as the solvent. Further, in the above reaction, an organic solvent may be appropriately used in addition to alcohols.

 Also, a catalyst containing Cu, Mn and / or Re at the same time can be used for the production of formate.

The resulting formate can be purified by a conventional method, but can also be directly used for the production of methanol. That is, methanol can be produced by hydrogenolysis of formate. A hydrocracking catalyst is used for the hydrocracking. For example, a general hydrocracking catalyst of Cu, Pt, Ni, Co, Ru, or Pd system can be used. C uZMn Ox C u / R e O x ( value X is acceptable chemically) to, C u / Z n O, C u / C r 0 3, copper-based catalyst such as Raney copper, and La Is preferably a nickel-based catalyst. Among _{them, C u / Mn O x,} C u / R e O x has a very high activity in the reaction, water and / or diacid carbon can be obtained a high yield of methanol be mixed. The preparation of these catalysts may be carried out by a conventional method such as an impregnation method, a precipitation method, a sol-gel method, a coprecipitation method, an ion exchange method, a kneading method, and an evaporation to dryness method, and is not particularly limited. According to the precipitation method, a catalyst with a high loading ratio can be prepared, and good results are easily obtained. In the present invention, by allowing these hydrocracking catalysts and hydrogen to coexist in the reaction system for producing formate from carbon monoxide and alcohols, it is possible to produce methanol in a so-called one step. . This hydrocracking reaction can be basically performed under the above reaction conditions, but the temperature and pressure may be appropriately changed. In this case, the ratio of hydrogen Z to carbon oxide is generally selected from about 115. As described above, when performing the reaction in the presence of the hydrocracking catalyst with an alkali metal catalyst or the like, the mixture may be used as a simple mixture. It is preferable that the catalyst be supported, because the catalyst can be easily recovered. The supporting method itself can be based on a conventional method for preparing the catalyst.

 If it is difficult to produce methanol in one step, the separated formate ester is separated, and then the separated formate ester is hydrocracked in the presence of a hydrocracking catalyst and hydrogen to obtain methanol. It is also possible.

The method for producing formate and methanol in the present invention is presumed to be based on the following reaction formula (the case where the alcohol is a chain or alicyclic hydrocarbon having a hydroxyl group is shown as an example. ). R— OH + CO → HCOOR (1)

HC O OR + 2 H ₂ → CH ₃ OH + R-OH (2)

 (Where R represents an alkyl group)

Therefore, the raw materials for producing methanol are carbon monoxide and hydrogen, and the alcohols can be recovered and reused. According to the method of the present invention, even if water and carbon dioxide are present in a large amount in the raw material gas (for example, at least 5% for carbon dioxide), the activity of the catalyst is not lost, and the formate ester is not lost. , Methanol can be obtained. Furthermore, even if the reaction system is contaminated with an iodide compound such as H ₂ S, HC1, or the like, and a chlorine compound, formate and methanol can be obtained without any problem. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

 The CO conversion and methanol yield described in the following Examples were calculated by the following equations, respectively.

CO conversion (%) = [1 - (CO + CO ₂ moles recovered after the reaction) / (the charged CO + C 0 ₂ moles)] XI 0 〇 methanol yield (%) = ((generated (Mole number of methanol) / (Molar number of charged CO + C 0 ₂ )) X 100 Example 1

Using an autocrepe with an internal volume of 80 ml, 0.72 mmol of lithium carbonate was added to 10 ml of ethanol containing 1% by mass of water as a solvent. The reaction gas was charged at 3 MPa with an acid gas mixed synthesis gas (CO 3 2%, CO ₂ 4.7%, hydrogen puls) at 170 ° (: 2 hours, and the reaction product was analyzed by gas chromatography. Only ethyl formate was obtained at a CO conversion of 3.0%.

 Example 2

 The reaction was performed by the method described in Example 1 except that the reaction time was set to 20 minutes. The same results as in Example 1 were obtained, and it was clear that the reaction reached equilibrium in 20 minutes.

 Example 3

 The reaction was carried out in the same manner as in Example 1 except that potassium bicarbonate was added instead of potassium carbonate. As a result, ethyl formate was obtained at a CO conversion of 3.1%.

 Example 4

 The reaction was performed by the method described in Example 1 except that cesium carbonate was added instead of calcium carbonate. Similarly, the CO conversion was 3.2%.

 Example 5

 The reaction was carried out by the method described in Example 1 except that sodium carbonate was added instead of carbon dioxide. Similarly,. 0 Conversion rate was 1.36%.

 Example 6

 The reaction was carried out in the same manner as in Example 1, except that lithium carbonate was added instead of potassium carbonate. Similarly,. 0 Conversion rate was 0.4%.

 Example 7

The reaction was performed by the method described in Example 1 except that nitric acid lime was added instead of carbonic acid lime. Similarly, when the CO conversion rate is 1.0% Was.

 Example 8

 The reaction was carried out by the method described in Example 1 except that sodium nitrate was added instead of carbon dioxide. Similarly,. 0 Conversion rate was 0.9%.

 Example 9

 The reaction was carried out in the same manner as in Example 1 except that calcium phosphate was added instead of carbon dioxide. Similarly, the conversion was 1.7%.

 Example 10

 The reaction was carried out by the method described in Example 1 except that potassium acetate was added instead of potassium carbonate. Similarly, the conversion rate of 00 was 1.51%.

 Example 1 1

 The reaction was carried out by the method described in Example 1 except that potassium formate was added instead of carbon dioxide. Similarly, the CO conversion was 3.44%.

 Example 1 2

 The reaction was carried out by the method described in Example 1 except that methanol was used instead of ethanol. CO conversion was 4.0% (methyl formate

) o

 Example 13

 The reaction was carried out as described in Example 1 except that n-propanol was used instead of ethanol. The CO conversion was 3.4% (n-propyl formate).

 Example 14

Example 1 except that n-ptanol was used instead of ethanol Reactions were performed as described. The CO conversion was 3.4% (n-butyl formate).

 Example 15

 The reaction was carried out as described in Example 1 except that i-propanol was used instead of ethanol. The 0〇 conversion was 1.1% (i-formic acid—propyl).

 Example 16

 The reaction was carried out as described in Example 1 except that i-butanol was used instead of ethanol. The conversion rate was 1.8% (i-butyl formate).

 Example 17

 The reaction was carried out as described in Example 1 except that t-butanol was used instead of ethanol. The CO conversion was 0.7% (formic acid t Example 18

 The reaction was carried out by the method described in Example 1 except that 0.2 g of a copper / zinc coprecipitation catalyst was further added as a hydrocracking catalyst. Methanol was obtained with a C 2 O conversion of 2.9% and a methanol yield of 0.3%.

 Example 19

Using an autoclave with an internal volume of 85 ml, 1.4 mmol of calcium carbonate was added to 20 ml of ethanol containing 0.010% by mass of water as a solvent, and a mixed gas of carbon dioxide mixed gas (CO 3 2%, CO ₂ 4.7%, Hydrogen Balance) was filled with 3.OMPa, the reaction was performed at 170 ° (2 hours), and the reaction product was analyzed by gas chromatography. CO conversion 1 At 6%, only ethyl formate was obtained.

 Example 20

Further add 4.0 g of copper-zinc coprecipitation catalyst as hydrocracking catalyst Otherwise, the reaction was carried out by the method described in Example 19. Methanol was obtained with a CO conversion of 25% and a methanol yield of 1.2%.

 Example 2 1

 The reaction was carried out by the method described in Example 19 except that 4.0 g of a copper-Z manganese coprecipitation catalyst was further added as a hydrocracking catalyst. Methanol was obtained with a CO conversion of 90% and a methanol yield of 27%.

 Example 22

 The reaction was carried out by the method described in Example 19 except that 2.0 g of a copper-Z manganese coprecipitation catalyst was further added as a hydrocracking catalyst. Methanol was obtained with a CO conversion of 79% and a methanol yield of 27%.

 Example 2 3

 The reaction was carried out in the same manner as in Example 19, except that 1.0 g of a copper-manganese coprecipitation catalyst was further added as a hydrocracking catalyst. Methanol was obtained with a CO conversion of 33% and a methanol yield of 1.1%.

 Example 2 4

Besides the mixed synthesis gas contains no C 0 ₂ Reaction was conducted in the procedure described in Example 2 2. Methanol was obtained with a CO conversion of 92% and a methanol yield of 41%.

Claims

The scope of the claims 1. A formate ester produced by reacting carbon monoxide with an alcohol to produce a formate ester in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst. Manufacturing method.  2. When producing formate by reacting carbon monoxide and alcohols in the presence of an alkali metal catalyst and a di- or alkaline-earth metal catalyst, the reaction system further comprises a catalyst for hydrogenolysis of formate and A method for producing methanol, comprising producing hydrogen by co-existing hydrogen and hydrogenating a generated formate ester to obtain methanol.  3. —React the carbon oxides and alcohols in the presence of an alkali metal catalyst and a Z or alkaline earth metal catalyst to produce formate, separate the formed formate, and then hydrocrack it. A method for producing methanol, comprising obtaining a methanol by hydrogenating a separated formate in the presence of a catalyst and hydrogen.  4. Alcohols are reacted from carbon monoxide and hydrogen in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst, and a catalyst containing Cu and Mn and / or Re simultaneously. A method for producing methanol, comprising obtaining methanol by heating.  5. A method for producing a formate ester, comprising reacting carbon monoxide with an alcohol to produce a formate ester, the reaction being carried out in the presence of a catalyst containing Cu, Mn and Z or Re at the same time.  6. The production method according to any one of claims 1 to 4, wherein the alkali metal catalyst and the alkaline earth metal catalyst are a catalyst containing an alkali metal salt and an alkaline earth metal salt. 7. The hydrocracking catalyst is a solid catalyst. 4. The method for producing methanol according to claim 2, wherein the metal-based catalyst and / or the alkaline earth metal-based catalyst are supported and subjected to the reaction.  8. The production method according to any one of claims 1 to 5, wherein the alcohol is a primary alcohol.  9. A catalyst for methanol production comprising an alkali metal catalyst and / or an alkaline earth metal catalyst supported on a solid catalyst for hydrogenolysis of formate.  10. A methanol production catalyst comprising an alkali metal catalyst and a Z or alkaline earth metal catalyst, and a catalyst containing Cu, Mn and / or Re at the same time.  11. A catalyst for the production of formate esters, characterized by containing Cu and Mn and Z or Re at the same time.